Задание №10 — Чтение

An octopus is a sea animal with eight arms. Octopi live in seas throughout the world. An octopus can change colour quickly depending on its surroundings or its mood. It can be grey, brown, pink, blue, green, or even red if it is suddenly frightened. It can change the colour of its entire body in just three-tenths of a second. But the creature doesn’t simply take on the general pattern of its surroundings. Instead, it often mimics specific undersea objects, like plants or rocks, to disappear into the underwater scenery.

Although dolphins look like fish and live in water, they are actually mammals. There are more than 35 species, or types, of dolphins. They are divided into two groups: true dolphins and river dolphins. True dolphins live all over the world in either salt or fresh water. The most widespread species are the common dolphin and the bottlenose dolphin. River dolphins live only in South America and Asia. They prefer freshwater. The Amazon river dolphin is found in the Orinoco and Amazon rivers.

Dolphins are known for being intelligent and playful. They use sounds for communication among themselves as members of a school (also called a herd or a pod). Schools may consist of five to several thousand individuals. Often an entire school will function as a unit to accomplish some objective, such as trapping fish. Dolphins have some of the most elaborate acoustic abilities in the animal kingdom. They make a variety of sounds including whistles, clicks, squawks, squeaks, moans, barks, groans and yelps.

Unlike most other fish, sharks have skeletons composed of cartilage rather than bone. With a few exceptions, sharks have torpedo-shaped bodies — an efficient, streamlined design for fast-swimming predators. Bottom dwellers tend to be stout and heavy bodied. Sharks normally have tough, grey skin with toothlike scales. Sharks vary in colour from grey to cream, brown, yellow, slate, or blue and are often patterned with spots, bands, or marbling. The whale shark is the largest living fish. It can weigh up to 20 tons.

Corals live in all oceans of the world. Reefs are composed of numerous different species of coral. Coral reefs cover less than one percent of the earth’s surface. Certain species of fish spend their life among the corals. Because of the income coming directly from fishing in their waters, reefs provide resources and services worth billions of dollars every year. Millions of people around the world depend on coral reefs for food, protection and employment. These figures are impressive.

Corals have barely changed over the last hundred million years. They are the same as they were during dinosaur times. Corals actually comprise an ancient and unique partnership, called symbiosis. Several different types of corals together can form enormous colonies that are called coral reefs. Coral reefs are intriguing things. Coral reefs can grow so large that they can be seen from outer space. Although they only take up a tiny proportion of the world’s ocean, coral reefs contain more than a quarter of all ocean-dwelling creatures.

A coral reef is a hard natural structure under the sea that is formed from coral. Coral reefs are some of the most diverse ecosystems in the world. Coral reefs only occupy 0.1% of the area of the ocean but they support 25% of all marine species on the planet. People have long used coral skeletons to make jewelry. But this and other human activities have put many corals at risk. Rising ocean temperatures, oil spills, and chemical pollution harm corals. Boats that sail over reefs may also damage corals.